Thanks for the reply. I do have a service manual I downloaded. So I,m seeing about replacing the caps. on the power supply end and checking the rectifier. I'm try to see if I can over rate the new caps. a little bit because I can't find the exact values.
Thanks, Derek
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--- In TekScopes@..., "Tom Miller" <tmiller11147@...> wrote:
Do you have a service manual?
What does the calibration waveform look like?
How about using the HF rejection for the sync? How about the BW limit, what effect doe it have? Maybe there is some HF noise on the test signal that we can't see in the video.
Use the Norm sync mode and adjust the trigger level and show us what happens.
I would open it up and check the power supplies for voltage and ripple per the manual. It seems to be jumping sync at a periodic rate.
----- Original Message -----
From: dawtesla2
To: TekScopes@...
Sent: Monday, October 08, 2012 9:43 PM
Subject: [TekScopes] Jumpy trigger control on Tektronics 475
I got this oscilloscope a few days ago. I put up a 1 Khz sine wave (from PC sign wave gen.) to test it. But my sine wave won't stabilize. When stopped, it dances around a bit with a slight pulse. All this makes it difficult to make a proper frequency reading. It's a great scope except for that. Does anyone have any idea what the problem is?
Here's a video link
Thanks, Derek
dawtesla2@...
